Tahnee A. Kinsman

Effect of simulated altitude during sleep on moderate-severity OSA

Objective:  These studies were conducted to test the hypothesis that isobaric hypoxia would switch OSA to central sleep apnoea (CSA).

Sleep quality responses to atmospheric variation: Case studies of two elite female cyclists

Strategies applied during sleep to potentially enhance athlete performance use different atmospheric conditions. High altitude conditions are known to affect sleep adversely but the effects of mild-moderate altitude and O2 enrichment at mild altitude are uncertain. We performed case studies using two elite female road cyclists (mass and maximal aerobic power of 62 kg, 65.8 ml x kg(-1) x min(-1); 57 kg, 62.7 ml x kg(-1) x min(-1)) to examine changes in sleep for different atmospheric conditions applied throughout the preparation for, and during, an International Stage race. Conditions were: i) normoxia (600 m), ii) simulated moderate altitude (2650 m), iii) natural mild altitude (1380 m) and iv) O2 enrichment at mild altitude (30% O2@ 1300-1500 m). We measured respiratory disturbances, arousals, number of awakenings, blood oxygen saturation (SpO2), heart rate (HR), rapid eye movement sleep (REM) and deep sleep. Respiratory disturbances, SpO2 and HR responses were similar for both cyclists for all conditions. Compared with normoxia, both cyclists had somewhat reduced REM at natural mild altitude and moderate simulated altitude but differed in their REM and deep sleep responses to O2 enrichment. Compared with mild altitude, both showed increased awakenings and deep sleep with O2 enrichment. Only one cyclist clearly increased her REM sleep with O2 enrichment compared to mild altitude. Our data highlight two different sleep quality responses to atmospheric variation.

Altitude Tents Do Not Impair Performance Response To Short-term High-intensity Cycling Training: 1548 Board #3

PURPOSE: to examine whether sleeping at simulated altitude during seven days of racespecific high-intensity cycling training interferes with cycling performance. METHOD: Seven regionally competitive male cyclists completed seven days of high-intensity interval training at ~600m while sleeping each night in an altitude tent with an F1 O 2 of either ~30.5% (SL) or ~16.5% (ALT). There were two training sessions daily, each 90 minutes in duration composed of 66 maximal efforts of 5-15 seconds with competition work:relief ratios (1:1, 1:3, 1:6). We used a double blind, repeated measures crossover design with a 2-wk washout period between treatments. A maximal graded exercise test (GXT = 100W, inc. 50w every 5 mins) was completed before and 2D after each training block. A dietician ensured that daily carbohydrate intake during the seven days of interval training was >8g.kg-1.d-1. RESULTS: Peak power during the GXT (Mean+/-SD) was lower(1) following SL and unchanged(2) following ALT. Peak power during the GXT after interval training was higher following ALT than following SL(3) (1) 377±42 to 358±42 W, p=.17 (2) 367±42 to 376±39 W, p=.41 (3) 19W, 49 to -9W; 90%CL